package com.itheima.reggie.controller;

import com.baomidou.mybatisplus.core.mapper.BaseMapper;
import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.IOException;
import java.util.UUID;

/**
 * 文件上传和下载
 */
@Slf4j
@RestController
@RequestMapping("/common")
public class CommonController {
    @Value("${reggie.path}")
    private String basePath;
    /**
     * 文件上传
     * @param file
     * @return
     */
    @PostMapping("/upload")
    public R<String> upload(MultipartFile file){//必须跟前端的name保持一致
        //file是临时文件，需要转存到指定位置否则本次请求完成后临时文件会自动删除
        log.info(file.toString());

        String originalFilename = file.getOriginalFilename();
        //后缀名
        String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
        //使用UUID生成文件名
        String fileName = UUID.randomUUID().toString()+suffix;

        //假设文件目录不存在需要创建
        File dir = new File(basePath);
        if(!dir.exists()){
            dir.mkdirs();
        }

        try {
            file.transferTo(new File(basePath+fileName));
        } catch (IOException e) {
            e.printStackTrace();
        }
        //返回文件名
        return R.success(fileName);
    }

    /**
     * 文件下载
     * @param name
     * @param response
     */
    @GetMapping("/download")
    public void download(String name, HttpServletResponse response){
        //输入流读取文件内容
        try {
            FileInputStream fileInputStream = new FileInputStream(new File(basePath+name));

        //输出流将文件写回浏览器

            ServletOutputStream outputStream = response.getOutputStream();
            //设置图片文件
            response.setContentType("image/jepg");



            int len=0;
            byte[] bytes = new byte[1024];
            while((len = fileInputStream.read(bytes))!=-1){
                outputStream.write(bytes,0,len);
                outputStream.flush();
            }
            outputStream.close();
            fileInputStream.close();

        } catch (Exception ex){
            ex.printStackTrace();
        }
    }
}
